DE102021109410A1 - Non-invasive thermometer - Google Patents

Abstract

The invention relates to a coupling element (7) for a device (1) for determining and/or monitoring a process variable, in particular the temperature (T), the flow rate or the flow rate, of a medium (M) in a container (2) for attachment the container (2), and a device (1) with a coupling element (7) according to the invention. The coupling element (7) comprises a base body (8) with a contact surface (9) which is designed in such a way that the base body (8) can be placed flat against the container (2) by means of the contact surface (9), the base body (8 ) has a bore for receiving a sensor element (3.5) of the device (1) for determining and/or monitoring the process variable, and wherein a longitudinal axis (L) of the bore (8) runs tangentially to the contact surface (9).

Description

The invention relates to a coupling element for a device for determining and/or monitoring a process variable, in particular the temperature, the flow rate or the flow rate, of a medium in a container for attachment to the container, and a corresponding device with a coupling element according to the invention. The container is, for example, a container or a pipeline.

Although the coupling element according to the invention is also used for other types of field devices, the following description focuses on field devices in the form of thermometers without restricting the generality. Thermometers have become known in a wide variety of configurations from the prior art. There are thermometers that use the expansion of a liquid, a gas or a solid with a known coefficient of expansion to measure the temperature, or those that relate the electrical conductivity of a material or a quantity derived from it to the temperature, such as the electrical resistance when using resistance elements or the thermoelectric effect in the case of thermocouples. In contrast, radiation thermometers, especially pyrometers, use the thermal radiation of a substance to determine its temperature. The measurement principles on which they are based have each been described in a large number of publications.

In the case of a temperature sensor in the form of a resistance element, so-called thin-film and thick-film sensors and so-called thermistors (also referred to as NTC thermistors) have become known, among other things. In the case of a thin-film sensor, in particular a resistance temperature detector (RTD), a sensor element provided with connecting wires and applied to a carrier substrate is used, for example, with the rear side of the carrier substrate usually being metallically coated. So-called resistance elements, which are provided for example by platinum elements, are used as sensor elements, which are also commercially available under the designations PT10, PT100 and PT1000, among others.

In the case of temperature sensors in the form of thermocouples, on the other hand, the temperature is determined by a thermal voltage that arises between the thermowires made of different materials and connected on one side. Thermocouples according to DIN standard IEC584, e.g. thermocouples of type K, J, N, S, R, B, T or E, are usually used as temperature sensors for temperature measurement. However, other pairs of materials, in particular those with a measurable Seebeck effect, are also possible.

The accuracy of the temperature measurement depends sensitively on the respective thermal contacts and the prevailing heat conduction. The heat flows between the medium, the container in which the medium is located, the thermometer and the process environment play a crucial role here. For a reliable temperature determination, it is important that the respective temperature sensor and the medium are essentially in thermal equilibrium, at least for a specific time that is required for detecting the temperature. The time it takes for a thermometer to respond to a change in temperature is also known as the thermometer's response time.

A high measurement accuracy can be achieved in particular when the temperature sensor is immersed in the respective medium. Numerous thermometers have become known in which the temperature sensor is brought into contact more or less directly with the respective medium. A comparatively good coupling between the medium and the temperature sensor can be achieved in this way.

However, non-invasive determination of the temperature is more advantageous for various processes and for many containers, in particular small containers or pipelines. Thus, thermometers have also become known which can be attached from the outside/inside to the respective container in which the medium is located. Such devices, also known as surface thermometers or contact sensors, are known, for example, from documents such as DE102014118206A1 or DE102015113237A1 known. With such measuring devices, the temperature sensors are not in direct contact with the respective process. This requires that to ensure good thermal coupling, several additional aspects need to be considered. For example, the mechanical and thus also the thermal contact between the container and the thermometer is decisive for the measurement accuracy that can be achieved. If there is insufficient contact, an accurate temperature determination is not possible.

Measuring inserts with temperature sensors in the form of thermocouples are often used as surface or skin point thermometers, which are welded directly to the outer surface or skin of the pipe or container. In such cases, however, the replacement of the thermocouples is possible become a time-consuming and costly process, particularly as replacement may require a temporary shutdown of the process and/or application. To overcome these disadvantages, for example, from the US5382093 or the previously unpublished European patent application with the file number 18198608.4 in each case configurations of corresponding thermometers have become known, which allow a simple exchange of the temperature sensors.

In addition, numerous different configurations of thermometers for non-invasive temperature measurement have become known, for example in the documents US2016/0047697A1 , DE102005040699B3 , EP3230704B1 or EP2038625B1 described.

A central problem with non-invasive temperature determination is the heat dissipation from the process to the environment. This causes a significantly higher measurement error than in the case of a direct introduction of the respective temperature sensor into the process.

The same problem also arises, for example, in the case of a flow meter based on the thermal measurement principle for determining a flow rate or a flow rate of a medium in a pipeline. Such field devices typically include at least two sensor elements with at least one temperature sensor and at least one heating element or heatable temperature sensor. The sensor elements can be introduced into the respective pipeline as well as integrated into or onto a measuring tube (non-invasive construction).

Proceeding from the described problem of heat dissipation in non-invasive temperature determination, the object of the invention is to provide a possibility with which the non-invasive determination of the temperature of a medium, in particular the measurement accuracy, can be improved.

This object is achieved by the coupling element according to claim 1 and by the device according to claim 12. Advantageous configurations are the subject matter of the dependent claims.

With regard to the coupling element, the object on which the invention is based is achieved by a coupling element for a device for determining and/or monitoring a process variable, in particular the temperature, the flow rate or the flow rate, of a medium in a container for attachment to the container, which coupling element has a Base body with a contact surface, which is designed in such a way that the base body can be placed flat against the container by means of the contact surface, wherein the base body has a bore for receiving a sensor element of the device for determining and/or monitoring the process variable, and wherein a longitudinal axis of the Bore is tangential to the contact surface.

The coupling element is used for the targeted distribution of heat from the process to the sensor element and thus to improve the thermal contact or to ensure thermal equilibrium between the wall of the container and the sensor element.

The bore is designed to accommodate the sensor element, in particular a temperature sensor, which is preferably arranged in a measuring insert. The sensor element that can be introduced into the bore is accordingly arranged or aligned relative to the container by the coupling element. A tangential course of the bore relative to the contact surface is understood below to mean different possible arrangements which have in common that a longitudinal axis runs through the bore in a plane parallel to a tangent to the typically curved wall of the container. Depending on the design, for example, a distance between a particular imaginary point of contact of the tangent and the longitudinal axis of the bore or an angle between the tangent and the longitudinal axis of the bore can be different. In addition, numerous other variants are conceivable for the configuration of the coupling element, in particular of the sensor element that can be introduced into the bore, relative to the wall of the container, which also fall within the scope of the present invention.

The process variable, in particular the temperature, the flow rate or the flow rate, of the medium is accordingly determined indirectly via a wall of the container. Through the coupling element, in particular through the arrangement of the bore relative to the contact surface or relative to the wall of the container, a contact surface between the sensor element and a section of the wall of the container facing the sensor element is significantly enlarged. In this way, the conduction of heat from the medium via the wall of the container to the sensor element and possibly present connecting lines contacting the sensor element is significantly increased. In addition, a temperature gradient is reduced. These effects in turn all lead to improved measurement accuracy.

The avoidance of so-called heat conduction errors is a fundamental problem in the field of industrial temperature determination, regardless of whether a thermometer or a flow meter is used. In the case of invasive thermometers, the so-called minimum immersion depth in the respective process is often mentioned in this context, which should usually be at least ten times the diameter of the thermometer. If the thermal contact has deteriorated, for example through the use of a protective tube, the minimum immersion depth should be more than ten times the diameter of the thermometer. In the case of block calibrators, the minimum immersion depth is usually fifteen times the diameter of the reference thermometer used for calibration. In contrast, in the case of a non-invasive temperature determination, as in the case of the present invention, other measures must be taken to ensure a homogeneous temperature control of the respective sensor element. However, due to the very inhomogeneous heat input in such a measurement, this is significantly more complex than in the case of an invasive temperature determination. The use of a coupling element according to the invention represents a particularly effective measure in this context.

In the context of the present invention, it is conceivable, on the one hand, to insert the sensor element directly into the bore. However, it is also conceivable that the sensor element is part of a measuring insert, in particular an elongate measuring insert, which measuring insert can be introduced into the bore. The coupling element can have one or more bores, into which one or more sensor elements can be introduced. It is also conceivable to introduce several sensor elements into the same bore. In addition, a unit for heating and/or cooling an area surrounding the sensor element can also be introduced into a bore, together with or separately from a sensor element.

The device can optionally also have electronics. Alternatively, the electronics can also be a separate component that can be connected to the device. The coupling element can also be fastened to the container by means of all fastening means that are customary and suitable for a person skilled in the art, such as clamps or pipe clamps.

In contrast to various solutions known from the prior art, in which the measuring insert is placed on the container, for example perpendicular to a longitudinal axis of the container and accordingly comes into thermal contact via the end face, in the case of the present invention, the measuring insert is tangentially attached by means of the coupling element guided past a wall of the container. Correspondingly, the thermal contact between the sensor element and the wall of the container takes place via a lateral surface of the measuring insert. Such an arrangement offers various advantages: On the one hand, a comparatively compact or space-saving design can be achieved. In addition, the coupling element according to the invention causes a significantly improved heat conduction between the medium and the sensor element, and consequently a significantly improved measurement accuracy with regard to the determination of the process variable, in particular the temperature of the medium or a variable related to the temperature, such as the flow rate or the flow. This is achieved in that a distance between the wall of the container and the sensor element is minimal in the solution according to the invention by means of the coupling element in the area of a lateral surface of the sensor element. With a suitable design of the coupling element or the arrangement of the bore in the base body relative to the contact surface, the distance can be minimized in a particularly simple manner, which results in improved heat conduction. It is advantageously possible to achieve a distance that is significantly smaller than a corresponding distance in other arrangements of the sensor element relative to the container. In addition, the coupling element according to the invention can be used to achieve surface contact with the wall of the container, which also increases the heat conduction from the medium to the sensor element and, as a result, improves the measurement accuracy.

One embodiment includes that the device comprises at least one reference element for in situ calibration and/or validation of at least the temperature sensor, which is attached to the outer wall of the container, and which reference element consists at least partially of at least one material, for which material the calibration is required of the first temperature sensor relevant temperature range at least one phase transition occurs at at least one predetermined phase transition temperature, for which phase transition the material remains in the solid phase. In this regard, be on the EP02612122B1 referenced, to which reference is made in full within the scope of the present patent application.

A further configuration includes that the contact area is designed to correspond to a surface. In this way, a precisely fitting arrangement of the coupling element can be achieved relative to the wall of the container. Typical receptacles, ie containers or pipelines, have curved surfaces. In the case of a convex surface of a wall of the container, a concave contact surface of the coupling element is therefore advantageous, for example.

Another configuration includes that the contact surface consists at least partially of a deformable, in particular flexible or ductile, material which is designed in such a way that it can be adapted to a contour of the outer wall of the container. The contact surface can be adjusted accordingly to the surface of the wall of the container. This has the advantage that small differences in nominal diameters, deviations in shape and/or unevenness in the surface of the respective wall of the container can be compensated for by the coupling element.

One configuration of the coupling element includes the bore being closed in an end area, which end area is located in particular within a volume of the base body. The bore is therefore a blind hole into which the sensor element can be inserted.

In a further embodiment, the coupling element comprises a shank which extends out of the base body and ends in the bore. The shank is parallel to the bore and coplanar with the bore. It is preferably a tubular, in particular cylindrical, element for accommodating the measuring insert. The shank can be attached to the base body or can be made in one piece with the base body. In addition to improved mechanical stability and improved thermal insulation from the environment of the device, the shaft serves to improve heat conduction or heat conduction from the process to the measuring insert. In particular, by using a shank it can be achieved that a region around the measuring insert, in which an essentially homogeneous temperature distribution can be achieved, can be enlarged.

It is advantageous if the coupling element is designed and/or arranged in such a way that a longitudinal axis of the container, in particular a pipeline, and a longitudinal axis of the bore are arranged at a predeterminable angle, in particular perpendicular to one another. An angled arrangement of the bore relative to the longitudinal axis of the container allows particularly simple handling or simple assembly or removal of the sensor element into or out of the bore.

In one embodiment, the coupling element comprises a pipe section, which is arranged adjacent to the contact surface, which pipe section is used to carry the medium. In this case, the pipeline section and the coupling element can either be subsequently connected to one another or manufactured in one piece from the outset. In this case, it is basically a coupling element in the form of a T-piece for a pipeline.

A further configuration includes that in the area of the contact surface a unit comprising at least partially a material with anisotropic thermal conductivity, preferably a material at least partially containing carbon, in particular graphite or hexagonal boron nitride, is arranged, or the base body is arranged in a region or in the area of the contact surface consists of the material with anisotropic thermal conductivity. In this context, reference is made to the German patent application with the file number DE102017100267A1 referenced, to which reference is made in full within the scope of the present invention.

In one configuration of the coupling element, thermal insulation made of a thermally insulating material is arranged in a region of the base body facing away from the contact surface and the bore, which at least partially surrounds the base body, or the base body consists of the thermally insulating material in this region. Accordingly, this configuration includes thermal insulation from the surroundings of the coupling element and the container.

A further configuration of the coupling element includes that the base body consists of a thermally conductive material in a region facing the contact surface and the bore. This measure serves to further improve the heat conduction from the medium or from the wall of the container to the sensor element.

In one configuration of the coupling element, the base body is made up of at least two components, in particular in the form of a layered structure. It is therefore a multi-component or multi-layer structure.

A further embodiment includes that the base body is made at least partially from a sintered material or a composite material. In the case of a sintered material, it is also advantageous if the sintered material or composite material contains, at least in a partial area, a material with anisotropic thermal conductivity, in particular one containing carbon Material such as graphite contains.
It is also conceivable that the unit, which includes the material with the anisotropic thermal conductivity, is attached, in particular sintered, to the base body. In particular, the base body can also be a sintered body made of two or more layers.

It is also conceivable to produce the base body from a sintered material, in which an additional, second material is introduced at least partially, in particular completely. In particular, this additional material can be introduced at least partially into the pores of the sintered material. This material can be graphite, for example, where the graphite can be used in addition to or as an alternative to the above-mentioned function of targeted heat conduction, for example as a solid lubricant, through which solid lubricant a contact resistance between the base body and the container or the base body and the measuring insert is reduced can be. It should be pointed out that, in addition to graphite, other materials, in particular also as a solid lubricant, can also be considered and also fall within the scope of the present invention.

It is advantageous if the coupling element is designed in one piece and is produced in particular by means of an additive manufacturing process, preferably by means of a 3D printing process. Alternatively, it is conceivable that the coupling element has at least two coupling components, in particular manufactured separately from one another.

In a further embodiment, the coupling element finally includes fastening means for fastening the base body to the container. The fastening means are preferably at least partially an integral part of the coupling element. For example, the fastening means can be means for producing a clamping screw connection, a screw connection, a spring connection or the like.

In summary, numerous different configurations are conceivable for the coupling element according to the invention, which have a tangential course of the at least one bore relative to the contact surface or relative to the wall of the container on which the contact surface rests when fastened to the container. Some particularly preferred variants have been explicitly described above. However, possible configurations of the coupling element are in no way limited to the variants explicitly mentioned above. For example, a shell-like design of the base body or an at least partially hollow base body is conceivable. The present invention also includes scope for design with regard to the size of the coupling element relative to the diameter of the container. The coupling element can be both a comparatively large-volume component and also have a compact, in particular shaft-like or bowl-like shape. The coupling element, in particular the base body, can also be designed in one piece or in several pieces.

It is an advantage of the coupling element according to the invention that no changes to the field device itself are necessary to implement a non-invasive arrangement of a field device. In the case of a field device in the form of a thermometer, for example, a typical thermometer measuring insert can be used and inserted into the bore of the coupling element.

The object on which the invention is based is also achieved by a device for determining and/or monitoring a process variable, in particular the temperature, the flow rate or the flow rate, of a medium in a container comprising a sensor element and a coupling element according to at least one of the preceding claims.

The sensor element is preferably a temperature sensor, in particular in the form of a resistance element or a thermocouple. The sensor element typically also has connection lines, which can also be introduced at least partially into the bore of the coupling element. The sensor element and the at least one connection line are, for example, part of a measuring insert, in particular a casing element, which is introduced into the bore of the base body of the coupling element.

However, in addition to devices in the form of thermometers, flowmeters can also be considered for the present invention. In this case, the device preferably also comprises a heating element which can be attached to the outer wall of the container, in particular by means of the coupling element. The sensor element and an area surrounding the sensor element can be heated to a predeterminable temperature by means of the heating unit. Within the scope of the present invention, the term flow includes both a volume flow and a mass flow of the medium. A flow velocity or flow rate of the medium can also be determined.

For example, the flow can be determined in two different ways. According to a first measurement principle, a sensor element is heated in such a way that its temperature essentially remains constant. If the medium properties are known and at least temporarily constant, such as the medium temperature, its density or composition, the mass flow rate of the medium through the pipeline can be determined using the heating power required to keep the temperature at the constant value. The temperature of the medium is understood to mean that temperature which the medium has without an additional heat input from a heating element. With the second measuring principle, on the other hand, the heating element is operated with constant heating power and the temperature of the medium is measured downstream of the heating element. In this case, the measured temperature of the medium provides information about the mass flow. In addition, however, other measuring principles have also become known, for example so-called transient methods in which the heating power or the temperature are modulated.

The heating element can be designed, for example, in the form of a resistance heater, which, via the conversion of electrical power supplied to them, e.g. B. as a result of an increased power supply, are heated.

• 1: ein Thermometer zur nicht invasiven Temperaturmessung nach Stand der Technik;
• 2: mögliche Ausgestaltungen für ein erfindungsgemäßes Koppelelement, welches schematisch im an einer Rohrleitung befestigten Zustand dargestellt ist;
• 3: mögliche Ausgestaltungen für ein erfindungsgemäßes mehrteiliges Koppelelement und mögliche Befestigungsmittel zur Befestigung des Koppelelements an einem Behältnis in Form einer Rohrleitung;
• 4: eine mögliche Ausgestaltung für ein erfindungsgemäßes Koppelelement mit einer thermischen Isolation;
• 5: eine erste mögliche Ausgestaltung für ein einstückig hergestelltes Koppelelement; und
• 6: eine zweite mögliche Ausgestaltung für ein einstückig hergestelltes Koppelelement.

The invention is explained in more detail on the basis of the following figures. It shows:

• 1 : a prior art thermometer for non-invasive temperature measurement;
• 2 : possible configurations for a coupling element according to the invention, which is shown schematically in the state attached to a pipeline;
• 3 : possible configurations for a multi-part coupling element according to the invention and possible fastening means for fastening the coupling element to a container in the form of a pipeline;
• 4 : a possible configuration for a coupling element according to the invention with thermal insulation;
• 5 : a first possible configuration for a coupling element produced in one piece; and
• 6 : a second possible embodiment for a one-piece coupling element.

In the figures, the same elements are provided with the same reference numbers. The configurations from the various figures can also be combined with one another as desired. In addition, all of the figures relate to containers in the form of pipelines and field devices in the form of thermometers. However, the present invention is by no means limited to tubing or thermometers. Rather, the respective considerations can easily be transferred to other types of containers and field devices.

In 1 a schematic illustration of a thermometer 1 according to the prior art with a measuring insert 3 and electronics 4 is shown. The thermometer 1 is used to record the temperature T of a medium M, which is in a container 2, here in the form of a pipeline. For this purpose, the thermometer 1 does not protrude into the pipeline 2, but rather is placed on a wall W of the pipeline 2 from the outside for non-invasive temperature determination.

The measuring insert 3 includes a sensor element in the form of a temperature sensor 5, which in the present case includes a temperature-sensitive element in the form of a resistance element. The temperature sensor 5 is electrically contacted via the connecting lines 6a, 6b and connected to the electronics 4. While the thermometer 1 shown has a compact design with integrated electronics 4 , the electronics 4 can also be arranged separately from the measuring insert 3 in other thermometers 1 . Also, the temperature sensor 5 does not necessarily have to be a resistance element and the number of connection lines 6 used does not necessarily have to be two. Rather, the number of connection lines 6 can be suitably selected depending on the measuring principle used and the temperature sensor 5 used.

As already explained, the measuring accuracy of such a thermometer 1 depends to a large extent on the respective materials used for the thermometer and on the respective, in particular thermal, contacts, in particular in the area of the temperature sensor 5 . The temperature sensor 5 is in direct thermal contact, i.e. via the measuring insert 3 and via the wall W of the container 2, with the medium M. Heat dissipation from the medium M to the environment, which can lead to an undesirable temperature gradient in the region of the temperature sensor 5, also plays a major role in this context.

In order to address these problems in a suitable manner, an alternative embodiment for a non-invasive determination of a process variable, for example by means of the thermometer 1, is proposed within the scope of the present invention, as shown in the figures 2-6 is illustrated using some preferred, exemplary configurations.

The invention is based on the use of a coupling element 7, such as in 2 shown. As in 2c illustrated, shows that Coupling element 7 has a base body 8 with a contact surface 9, by means of which the base body 8 can be placed flat and in particular with a precise fit on the container 2, in particular the wall W of the container 2. The contact surface 9 is preferably designed to correspond to a surface O of the wall W of the container 2 . The base body 8 also has a bore 10 into which the sensor element 5 of the device 1 can be introduced, for example the measuring insert 3 with the sensor element 5 and the connecting lines 6a and 6b 1 . According to the invention, a longitudinal axis L _K of the bore 10 is tangential to the contact surface 9 of the coupling element 7, i.e. in a plane parallel to a tangent T to the contact surface 9 or wall W of the container 2.

In 2a is a first embodiment of a coupling element 7 according to the invention, in which an angle α between the longitudinal axis L _K of the bore 10 and a longitudinal axis L _B of the pipeline 2 is α=90° in the case of the coupling element 7 shown on the left, i.e. perpendicular to the longitudinal axis LB of the pipeline 2 is. In contrast, in the case of the coupling element 7 shown on the right, α=45°. It is also conceivable that the coupling element 2 has bores 10a and 10b, which each serve to accommodate a measuring insert 3a and 3b, as in 2 B illustrated. In the case of several bores 10a and 10b, the respective angles α can each be the same as in the case of FIG 2 B , or at least partially different.

Numerous different variants are also conceivable for the configuration of the base body 8, as for example in the figures 2d - 2f sketched. In accordance with the design 2d the base body 8 is designed in the form of a shell in order to enable a compact design. In accordance with the design 2e it is a large-volume base body 8, which can bring advantages in particular with regard to thermal insulation from the surroundings of the coupling element 7 and measuring insert 3. In addition, such a configuration is typically mechanically more robust. In accordance with the design 2f includes the similar to the case of 2e designed base body 8 also has a shaft 8a for receiving the measuring insert 3. The shaft 8a has various functions, in particular it serves to improve heat conduction from the wall W of the container 2 to the measuring insert 3 and to enlarge an area with a homogeneous temperature distribution around the measuring insert 3 . In addition, the shank 8a can serve to improve the thermal insulation and/or the mechanical stability of the device 1 or of the measuring insert 3 in the bore 10 of the base body 8 .

In 3 Various possible configurations for multi-part coupling elements 7 and for possible fastening means 13 are shown. In case of 3a the base body 8 is in two parts and is designed with a shaft 8a and has two coupling components in the form of half-shells 11a and 11b, which can be arranged around the pipeline 2. The bore 10 runs in the area of both half-shells 11a and 11b and is closed in an end area 12 . It should be pointed out that the base body 8 can also have more than two coupling components in other configurations, and that even in the case of two coupling components, these do not necessarily have to be configured in the form of half shells 11a and 11b. Rather, numerous different variants are conceivable, all of which fall under the present invention.

Various variants are also conceivable for fastening the coupling components, here the two half-shells 11a and 11b, to one another and for fastening the base body 8 to the container 2 . In the case of the in 3b In the embodiment shown, the coupling element 7 comprises fastening means 13 for producing a screw connection by means of two screws, which is used to fasten the two half-shells 11a and 11b to one another and to the pipeline 2 at the same time. In contrast, in the case of in 3c shown embodiment fastening means 13 are provided, which comprise a hinge and a screw. Other configurations may include other fasteners 13, such as those with fasteners, clamps, tensioners, straps, or springs. The fastening means 13 can be used both for fastening several components of the base body 8 to one another and for fastening the coupling element 7 to the pipeline 2 . However, separate fastening means 13 can also be used for these two purposes. In the case of a one-piece coupling element 7, only attachment to the container 2 is required.

In 4 a coupling element 7 with a unit 14 comprising a material with anisotropic thermal conductivity and thermal insulation 15 is shown. The unit 14 is arranged in an area of the base body 8 facing the container 2 , while the thermal insulation 15 is arranged in an area of the base body facing away from the container 2 and serves to insulate the coupling element or the device 1 from the environment.

A first possible configuration for a one-piece coupling element 7 is shown in 5 illustrated. The coupling element 7 has a base body 8 with an (optional) shaft 8a and a bore 10 for receiving a measuring insert 3 with a sensor element 5. The contact surface 9 lies flat against the wall W of the container 2. In this case, the surface of the contact surface 9 is as large as possible, in particular a maximum, while an expansion of the base body 8 perpendicular to the contact surface 9 is particularly small, in particular a minimum. On the one hand, this results in a particularly compact design. In addition, such a configuration also ensures reduced, in particular minimized, heat loss to the environment. This effect can be increased even further by taking suitable measures with regard to the design or construction of the base body 8, for example with regard to the internal heat conduction. In particular, the base body 8 can be designed in such a way that increased heat conduction from the contact surface 9 to the bore 10 or to the Shaft 8a takes place.

While it is in the case of 5a the base body 8 is a solid body, the in 5b shown base body 8 to a hollow body. A base body 8 in the form of a hollow body offers the additional advantage that the measuring insert 3 comes into direct contact with the wall W of the container 2 . This reduces the distance between the sensor element 5, which is arranged in the measuring insert 3, and the wall W of the container 2, to which the measuring insert 3 is arranged tangentially, which in turn results in a further improvement in the heat conduction from the medium M to the sensor element 5.

In 6 Finally, a shaft-like configuration of the base body 8 of the coupling element 7 is shown. This embodiment represents a particularly compact and simple design. For this embodiment, it is also conceivable to use a massive ( 6a) Body 8 and a body in the form of a hollow body ( 6b) to use. In addition to the two variants for a one-piece body 8 from 5 and 6 numerous other possible configurations for a base body 8 of a coupling element 7 according to the invention are conceivable, which also fall under the present invention. In particular, in the figures 5 and 6 configurations shown can also be combined with one another as desired.

In summary, it is an advantage of the present invention that a standard measuring insert 3, for example a thermometer 1, can be used to implement a non-invasive thermometer 1. For this purpose, the coupling element 7 according to the invention has a bore 10 for receiving the measuring insert 3 . An adaptation to the geometry of the container 2 takes place by means of the contact surface 9 of the coupling element 7. In contrast to other solutions known from the prior art, a longitudinal axis L of the measuring insert 3 runs tangentially to the wall of the container W, as a result of which improved heat conduction is achieved can.

Reference List

1

contraption

2

container

3

measuring insert

4

electronics

5

temperature sensor

6

connecting wires

7

coupling element

8th

body

9

contact surface

10

drilling

11

a,b Coupling components in the form of half-shells

12

end area

13

fasteners

14

Unit with anisotropic thermal conductivity

15

thermal insulation

M

medium

T

temperature

W

wall of the container

LB

longitudinal axis of the container

LK

Longitudinal axis of the coupling element

a

Angles between the longitudinal axes

T

tangent

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102014118206 A1 [0007]
• DE 102015113237 A1 [0007]
• US5382093 [0008]
• US 2016/0047697 A1 [0009]
• DE 102005040699 B3 [0009]
• EP 3230704 B1 [0009]
• EP 2038625 B1 [0009]
• EP 02612122 B1 [0022]
• DE 102017100267 A1 [0029]

Claims (15)

Coupling element (7) for a device (1) for determining and/or monitoring a process variable, in particular the temperature (T), the flow rate or the flow rate, of a medium (M) in a container (2) for attachment to the container (2 ), full a base body (8) with a contact surface (9) which is designed in such a way that the base body (8) can be placed flat against the container (2) by means of the contact surface (9), wherein the base body (8) has a bore (10) for receiving a sensor element (3.5) of the device (1) for determining and/or monitoring the process variable, and a longitudinal axis (L) of the bore (8) being tangential to the contact surface (9). Coupling element (7) after claim 1 , wherein the contact surface (9) is designed to correspond to a surface (O) of the container (2). Coupling element (7) after claim 1 or 2 , wherein the contact surface (9) consists at least partially of a deformable, in particular flexible or ductile, material which is designed such that it can be adapted to a contour of the outer wall (W) of the container (2). Coupling element (7) according to at least one of the preceding claims, wherein the bore (10) is closed in an end region (12), which end region (12) is located in particular within a volume of the base body (8). Coupling element (7) according to at least one of the preceding claims, comprising a shank (8a) which extends out of the base body (8) and opens into the bore (10). Coupling element (7) according to at least one of the preceding claims, wherein the coupling element (7) is designed and/or arranged in such a way that a longitudinal axis (L _B ) of the container (2), in particular a pipeline, and a longitudinal axis (L _K ) of the Bore (10) are arranged at a predetermined angle (a), in particular perpendicular to one another. Coupling element (7) according to at least one of the preceding claims, comprising a pipe section which is arranged adjacent to the contact surface and which pipe section is used to carry the medium (2). Coupling element (7) according to at least one of the preceding claims, wherein in the area of the contact surface (9) a unit comprising at least partially a material with anisotropic thermal conductivity, preferably a material at least partially containing carbon, in particular graphite or hexagonal boron nitride, is arranged, or wherein the The base body (8) consists of the material with anisotropic thermal conductivity in a region facing the contact surface (9). Coupling element (7) according to at least one of the preceding claims, wherein a thermal insulation (15) made of a thermally insulating material is arranged in a region of the base body (8) facing away from the contact surface (9) and the bore (10), which thermal insulation (15) 8) at least partially surrounds, or wherein the base body (8) consists of the thermally insulating material in the area. Coupling element (7) according to at least one of the preceding claims, wherein the base body (8) consists of a thermally conductive material in a region facing the contact surface (9) and the bore (10). Coupling element (7) according to at least one of the preceding claims, wherein the base body (8) is made up of at least two components, in particular in the form of a layered structure. Coupling element (7) according to at least one of the preceding claims, wherein the base body (8) is produced at least partially from a sintered material or a composite material. Coupling element (7) according to at least one of the preceding claims, wherein the coupling element (7) is designed in one piece and is produced in particular by means of an additive manufacturing process, preferably by means of a 3D printing process, or wherein the coupling element (7) has at least two, in particular separately from one another manufactured coupling components (11a, 11b). Coupling element (7) according to at least one of the preceding claims, comprising fastening means (13) for fastening the base body (8) to the container (2). Device (1) for determining and/or monitoring a process variable, in particular the temperature (T), the flow rate or the flow rate, of a medium (M) in a container (2) comprising a sensor element (5) and a coupling element (7). at least one of the preceding claims.

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